Power grids have a number of power producers and a number of power consumers connected thereto. The power producers produce power and deliver the produced power to the power grid. Various kinds of power producers may be connected to a power grid, such as fossil fuelled power plants, nuclear power plants, wind turbines, e.g. in the form of individual wind turbines or wind farms, photovoltaic power cells, hydropower plants, etc.
The larger conventional power producers, such as the fossil fuelled power plants and the nuclear power plants, provide a stable power production, which can be maintained constant on any desired time scale, but it may be difficult and often expensive to adjust the power production from these power producers, at least on a short time scale. Furthermore, the demand for energy defined by the power consumers connected to the power grid also changes, e.g. during the course of the day, during the course of the year, depending on outdoor temperature, etc.
In order to keep the power grid stable, it is desirable to essentially maintain a match between power supplied to the power grid by the power producers and power consumed from the power grid by the power consumers. In situations of a high power production and a low power demand, there is a risk of the power grid becoming unstable.
EP 2 733 810 A1 discloses a method of controlling a power network that includes a plurality of power generation facilities and a plurality of power storage facilities connected to the power generation facilities. In the case of excess power production by the power generation facilities, power may be stored in the power storage facilities, and in the case of power shortage, power from the power storage facilities may be consumed.